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Age-specific antibody to hepatitis E virus has remained constant during the past 20 years in Japan


Dr Eiji Tanaka, Department of Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. E-mail:


Summary.  We investigated the presence of antibodies to hepatitis E virus (anti-HEV) and hepatitis A virus (anti-HAV) by enzyme immunoassays in sera from 1015 individuals collected in 1974, 1984 and 1994. Age-specific profiles of anti-HEV remained unchanged with a peak at 40–49 years, while those of anti-HAV started to increase in individuals aged 20–29 years in 1974, 30–39 years in 1984 and 40–49 years in 1994. These results suggest that a silent HEV infection has been taking place in the last 20 years or so in Japan, while HAV infection has been terminated at least since 1974.